The present invention relates to a device for sampling for analysis a liquid in which precipitating solid particles are suspended (hereinafter referred to as a slurry) and which is kept in a column or tank of an exhaust gas cleaning apparatus or waste water treating apparatus or the like which uses such slurry, and to a method for sampling such slurry for analysis.
A wet lime exhaust gas desulfurizer functions to clean an exhaust gas containing SO.sub.2 or the like, such as boiler exhaust gas, through desulfurization with a slurry which is formed by suspending, for example, fine particles of limestone into water and which is kept in a column or tank.
The analysis for the composition of the slurry in such an apparatus has been carried out by quantitative and manual sampling of a small amount of sample required for the analysis with a pipet, and pouring it into an analyzer.
To automate the analysis, there has been adopted such a system as illustrated in FIG. 3, in which liquid in a column or tank 9 is collected through a tube by means of a quantitative semimicropump 8, and quantitatively transferred into an analyzer 6. When an object to be collected is clarified liquid, the above system does not cause any trouble.
However, if an object to be collected is a slurry in which precipitating solid particles are suspended, some solid particles precipitate and deposit in the sampling system, so that the following troubles have conventionally been observed:
1) Analytical accuracy deteriorates;
2) Stable and continuous analysis over a long period of time is impossible due to the clogging of pipes;
3) As a result, analytical data cannot be utilized for process control during the operation of an apparatus; and
4) Maintenance is troublesome.